You, personally, may not require as much as 3’ of clearance, but you will need lots of room. Turntables are usually located on top of a rack or table, so access is not an issue. However, if its necessary for you to reach between shelves to make adjustments, the clearance between the table and the shelf above it should be adequate to comfortably accommodate your head, shoulders, and arms without risking a collision with the table as you move around. If you’re an NFL nose tackle, that could mean a minimum of 5 feet. Rich

1. I think the height of the shelf depends most on the sight lines. If you stand and look down at the turntable, I think it would be best if you can comfortably see the back edge of the turntable (and a little extra). It would be a bit off-putting if the top shelf cuts off the view, and if the top shelf will hit your head if you took another step. This would depend on the depth of the turntable and free area needed at the back of the turntable, and the height of the shelf from the ground, and your own height. (You'd have to have a fair bit of clearance in the back, because of the RCA sockets in the back.)

2. What if the sides had a lot of openings/holes? What if it was more open than solid? Ditto for the top shelf and even the bottom shelf - subject, of course, to strength considerations. The more openings there are, the more the volume of air will be connected to the air in the rest of the room, and this will reduce the magnitude of the resonance. If the sides need to look solid, then may be it can be covered with fabric. You can still have a door - close and lock it to protect your gear, then open the door and leave it open during listening sessions.

Sorry for the belated reply, I had gotten the dimensions I was looking for on a dust cover's clearance and thought this thread had run it's course.

Golear, good idea on the doors since i recently can to the same conclusion as an alternative to using a dust cover. Im considering whether to use one pair of doors to cover all the components, leaving them open when playing, closed when not, or Dutch type double doors so I can close off the turntable when playing records while leaving the other components open to the room for natural ventilation.

The only opening to air in the room will be the front, the sides and top would open to an attic space. I will be drilling holes behind the Turntable on its shelf to run wires and help the component on the shelves below to vent. You've given me a few things to think about. Thanks for you consideration. I wish I had three feet to play with for the turntables shelf. That would push the Flat screen tv mounted over that shelf too high and give me a crook in the neck. I will make it a large as possible without creating a resonant air chamber, yet another issue I've been warned about over on Audiogon. And I thought this was going to be easy.

Peer Gynt, with you input maybe I'll rethink having a Dutch door to close over the turntable opening. I'v got to think this out more thoroughly before wasting materials.

Mr. Putty, I am a woodworker. I will be using marble on a anti-vibration pad over an existing plywood shelf, and will hope the Classic 2's feet damp any of the marbles own resonance adequately. I had been considering metal clips on adjustable tracks for the rest of the equipment, the shelves being free floating, and the clips being covered with sorbothane or something similar. Thanks for you ideas.

Thanks all for your well thought out input and sorry again for my delay replying.